What is Biology? The science of living organisms and life processes, including the study of structure, functioning, growth, origin, evolution and distribution of living organisms

Organism An individual living thing

All organisms… Consist of one or more cells Reproduced based on DNA Gain energy from their environment via metabolism Use energy and matter from the environment to grow and develop Maintain a separate internal environment to maintain homeostasis Are the product of evolution

tissue organ organ system molecule cell atom

community ecosystem multicelled organism population the biosphere

The Organization of Life Cell Tissue Organ Organ System Multicellular Organism Population Community Ecosystem Biosphere

The Scientific Method The main steps of the scientific method Observation The main steps of the scientific method Question Hypothesis Prediction Test does not support hypothesis; revise hypothesis or pose new one Test supports hypothesis; make additional predictions and test them Test: Experiment or additional observation Figure 1.3A

Deductive reasoning is used in testing hypotheses If a hypothesis is correct, and we test it, then we can expect a particular outcome Case study: flashlight failure Figure 1.3B

Scientific Theory An explanation of the cause or causes of a range of related phenomena. Scientific theories, unlike common theories, have been rigorously tested but are still open to testing, revision, and tentative acceptance or rejection.